Earthquakes trigger undersea methane reservoirs: study

July 28, 2013

Seagulls fly over the Arabian Sea during sunset, in Mumbai on December 20, 2010. Earthquakes can rip open sub-sea pockets of methane, a highly potent greenhouse gas, according to a study by German and Swiss scientists published on Sunday.

Earthquakes can rip open sub-sea pockets of methane, a highly potent greenhouse gas, according to a study by German and Swiss scientists published on Sunday.

Quake-caused methane should be added to the list of heat-trapping carbon emissions that affect the world's climate system, although the scale of this contribution remains unclear, they said.

The evidence comes from cores of sediment drilled from the bed of the northern Arabian Sea during a research trip by marine scientists in 2007.

One of the cores has now been found to contain methane hydrates—a solid ice-like crystalline structure of methane and water—only 1.6 metres (5.2 feet) below the sea floor.

Also uncovered were tell-tale signatures from water between sediment grains, and concentrations of a mineral called barite.

Together, these suggested that methane had surged up through the sea bed in recent decades.

"We started going through the literature and found that a major earthquake had occurred close by, in 1945," said David Fischer from the MARUM Institute at the University of Bremen.

"Based on several indicators, we postulated that the earthquake led to a fracturing of the sediments, releasing the gas that had been trapped below the hydrates into the ocean."

Their search names the culprit as an 8.1-magnitude quake, the biggest ever detected in the northern Arabian Sea.

It ruptured a shallow gas reservoir at a location called Nascent Ridge, according to their paper, appearing in the journal Nature Geoscience.

Over a likely period of decades, around 7.4 million cubic metres (261 million cubic feet) of methane—equivalent roughly to 10 large natural-gas tankers—belched to the surface, the authors calculate.

This estimate is conservative, they stress, adding that there could well be other sites in the area that were breached by the quake.

Greenhouse gases have both natural and man-made sources.

Identified natural sources include volcanic eruptions, which disgorge heat-trapping carbon dioxide (CO2) as well as cooling sulphur dioxide particles, and methane from land and thawing permafrost.

The biggest human source is CO2, from the burning of coal, gas and oil, and methane caused by deforestation and agriculture.

Methane has become a rising concern in the global warming equation because it is 25 times more effective than CO2 in trapping solar heat, although it is also shorter-lived.

According to estimates published last week in Nature, the leakage of 50 billion tonnes of methane from the thawing shoreline of the East Siberian Sea—part of the Arctic Ocean, which is one of the Earth's hot spots for warming—would inflict costs almost as big as the world's entire economic output.

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19 comments

"According to estimates published last week in Nature, the leakage of 50 billion tonnes of methane from the thawing shoreline of the East Siberian Sea—part of the Arctic Ocean, which is one of the Earth's hot spots for warming—would inflict costs almost as big as the world's entire economic output."

Gavin Schmidt of James Hansen's old NASA office, icon of the "hockey stick team" of Climategate infamy has himself roundly ridiculed this Nature journal promotion of the madness of crowds. One of his round of extensive Twitter comments:

"No evidence in ice cores of spike in CH4 for recent periods in the past with warmer Arctic (~8000 yrs ago or ~125,000 yrs ago) (3/n)"

Well, I'm sure it will soon be "proven" that the earthquakes were caused directly by the fracking of the evil Exxon, whose employees made it doubleplusungood by driving their SUVs to the drilling sites.

Aha --first on the scene with the usual moron denialist comments are geokstrap and NikNikFromDickCity.

One claims to be a "scientist" and the other claims to own a brain. I'll leave it to other readers and commentors to debate which of the two claims is the more dubious, as there is certainly no merit to be found in either's comments.

Madcap bungle: to use bots to auto down rate skeptical comments but then impulsively spit debate unworthy bile below, to five star inform casual filter users that skeptical comments exist behind their filter setting! And you want these people as policy advisors? Rating them five stars only takes a second and helps expose the real face of Global Warming "science."

Gavin Schmidt also runs the web site RealClimate.org during work hours at NASA, a site registered by Environmental Media Services, which is a division of the PR firm behind both the autism/vaccine scare and the junk science of silicone breast implants suits that bankrupted Dow Corning, and he now informs activist scientists of the folly of equating opposition to denial:

"he now informs activist scientists of the folly of equating opposition to denial:" NikkieTard

Actually Schmidt says nothing of the kind if the link NikkieTard provides. In fact, what Schmidt says is that one should not link Global Warming Denialism with Holocaust Denialism because it will upset the denialists.

But clearly there is much in common with Holocaust denial and global warming denial, even though Schmidt would rather not see that fact widely presented.

In 2009 the Arab oil money hero and quite literal Holocaust denier, the president of Iran, gave a Global Warming speech at the Copenhagen event:

"If greenhouse-gases continue to increase at the present speed, they will reach twice the level of gases before industrialization. In other words, instead of a reduction of 50 per cent, they will increase by 50 per cent and will pose a real challenge to the natural environment."

"he now informs activist scientists of the folly of equating opposition to denial:" NikkieTard

Actually Schmidt says nothing of the kind if the link NikkieTard provides. In fact, what Schmidt says is that one should not link Global Warming Denialism with Holocaust Denialism because it will upset the denialists.

But clearly there is much in common with Holocaust denial and global warming denial, even though Schmidt would rather not see that fact widely presented.

When did questioning and analyzing scientific speculations become "denial". It is THE most important part of scientific investigation. It is a sad day for science when the scientific method has been thrown away for religious zealotry. It seems if the priests say so no one had better disagree. Very sad.

When did questioning and analyzing scientific speculations become "denial". It is THE most important part of scientific investigation. It is a sad day for science when the scientific method has been thrown away for religious zealotry. It seems if the priests say so no one had better disagree. Very sad.

There is informed speculation; and then there is unfounded speculation. The denialists present here are for the most part those who engage in the latter; the balance simply deny that which may have consequences that they don't like.

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